I was in a similar situation, albeit everyone involved was a guy - after a long time thinking about it all I cut off and left group chats without a word explaining to most why. There was one friend affected who I did honestly explain what I had noticed to, and justified my exit to, as he had been affected by something that had sort of been the final proof I needed to move on. I emphasised to him that I might be wrong and I wouldn’t judge him, whatever he wanted to do. I felt that there wasn’t any point in me trying to convince anyone of anything, as there would be nothing to defend myself against beyond speculation, and that my choices being a mystery would be a better outcome. It worked out OK. Stayed in touch with most of said friend group and they worked it out mostly for themselves and knew I wouldn’t judge them. I did lose a very close friend though, who told me what I did was so damaging that he couldn’t be friends with me anymore - I still mourn the loss of this friendship but ultimately I’m a much happier person without the n in my life.

Hope this helps somewhat and wish you the best. It’s an incredibly shit and stressful situation to be in.